Relay for high-tension fuses



Feb. 21, 1928.

P. C. MCKENDRICK RELAY FOR HIGH TENSION FUSES Filed May 25, w25 2 Sheets-Sheet l 3mm/toi flttomag Maen/01H07 Feb. 21, 1928.

P. C. MCKENDRCK RELAY FOR HIGH TENSION FUSES Filed May 25, 192

eets-Sheet 2 n/uentoc .Mclendric Paul C Patented Feb. 122%.

PAUL C. MCKENDRICK, GEF ST. PAUL, MNNESOTA.

'aunar non nrenann'sioir rusas.

Application led "May 25, 1925. Serial No. 32,552.

soon as the power fails, and in the case of a short circuit, especially in high-power supplylines, the short circuit will usually burn through or meltl the object which caused the short circuit and thereby clear t-he line. lf a second fuse is inserted after a time interval, the circuit will be again in a conditionfor operation. l f

Fuses are frequently placed at comparatively great distances from the source of power, and from a service station and where it` is necessary to replace blown fuses by hand it frequently entails a long andunnecessai'y delay andconsiderable expense.

An object of the present invention is to mechanically replace a blown lfuse in a circuit with a fresh fuse after a predetermined time interval.

Another object is to hold a trip means in an inoperative condition by means of a fuse wire and tofrclease the trip means upon the brea g of the fuse wire to operate a time mechanism which will replace the fuse, afterA a predetermined time interval, with a fresh fuse. l 4 These and other objects of the invention,

vnot specifically mentioned, will be more fully broughtout in the following description and the accompanying drawings,where-A Figure 1, 1s a View in top elevationl of -a device made in accordance with the present invention, a part thereof being broken away to show the operative structure of the device.

` through a Figure 2, is an end elevation of the device`I shown in Figure 1, the end of being broken away `to show mounting a fuse therein.

Figure 3, `is a view in vertical section fuse shown in Figure 1.

Figure 4, is an enlarged view of a liquida fuse housing a meth/od of releasing mechanism.

Figure 5,7is aview in side elevation of a fluid release member: p p l Figure 6, isa view of the same structure as shown in Figure 5, rotated through an an-v gle of ninety degrees. y

Figure 7, is a view in top elevation of the device shown in Figure 5 g and small platform trof insulative material `to be lll.

box-like housings 2 and 3 are constructed of4 a suitable insulative material to house a pair of fuses to'be later described in detail. A.

is mounted on supports 5 and is aiiixed to the mounting plate 1 in a suitable manner, as by screws, not shown. A. fuse A, preferably having a structure such as that specifically illustrated in Figure 3, is mounted within the housing 2 by means of a contact clips 6 of a ywell known type. body of the fuse comprises a tube 13 able insulative The of suitmaterial. i conductive ring 7, which may be of bronze, encircles the lower end of fuse A, and has extending from the lower end thereof a projection 8 to which a lower terminal member 9 of a fusible element 10 may be connected by means of' a screw 11`which threadedly engages the projection 8. 'lhe fusible element is preferably thinned at 12 to `fuse atfthis point when subjected to a predetermined excess of current over that which^it is designed to nor-f mally carry. v

Having a tight, slidable lit within the tubular member 13 ofthe fuse are a pair of insulated bushings' 14 .and 15, which aneintended to reduce the diameter of the interior of tubular member B and provide an'explosion chamber of enlarged diameter intel-me#A diate the ends of the tubular bushings.

An insulating partition 16, having a central opening 17 therethrough, is axed transversely of the tubular member 13 to be closely adjacent the upper end of upper bushing 15. An annular metal Contact member 18, having a threadedy central opening, is axed to the upper end Mof the tubular member 13 ber 19, having a ho e drilled centrally longitudinally thereof, threadedly engages' the threaded opening in annular contact member 18. i A plunger rod 20 is slidably mounted within the central longitudinal epening of annular contact member 19 to slide freely therein, and is provided with a screw 21 at its lower end by means-of which the upper end of the fusible element 10 may be connected to the pair of spring gripped by cli s 6. A threaded mem-V plunger rod.` A cpil spring 22, having its upper end permanently connected to the threaded member 19, has the lower end thereof secured to plunger' rod 20, and is held in tension intermediate the 5 `threaded member and the plunger rod when a fuse element is connected tothe plunger f Vrod by means of the screw 21. The upper portion of the plungerA rod is threaded, and a fnut 23 is threadedly mounted thereon. I.A tuff) bular sleeve 24, which may be of insulative material, is mounted upon the plunger yrod to rest uponthe nut 23 and a trip member B rests upon the insulativesleeve 24, as shown. vA second nut 25 threadedly engaging Ithe plunger rod holds the sleeve and Vtrip members firmly in compression between the two nuts to retain the parts in position.

The trip member B comprises a strip of metal bent at 26- to form a-right angle, and i9 at 27 to form a second right angle. rI he central vertical portion is slidably mounted upon a plate 28\by means of a pair of guldes, the plate 28 being integrally secured to the side of the fuse housing 2. 4The trip mech- 35 anism is shown in solid lines in a set condition and in dotted lines in an actuated condition. i

The plunger rod is ynormally held in a lowered or set position by means of the 3U fusible element 10, the parts having the d, positionsv shown in slid lines in Figure 1, and are released to assumethe dotted line position shown'in Figure 1, `upon the breakvf \ing of fusible member 1() by the action ,of

the spring 22.

A'timing mechanism C is mounted upon the base 1 by means of clips, not shown, of a well known type. A cylindricalchamber 29 is provided with a metal extension 30 af- 10 jfixed to the top thereof, as by welding, the

upper end of the extension being bent inwardly to 'extend transversely of the cenv .tral axis of thetubular chamber 29. A hole is drilled in the inwardly extending portion of member' 30 of a Size t0 receive the stemf 31 of a metal valve 32. A sleeve 33 is adjustably connected to the valve stem 31 'by means of a screw, to permit the sleeve to be adjusted longitudinally of the valve stem.

The valve stem enters the interior of the Vtubular'chan'iber 29 through a packing nut 34 of a well known type, so as to make a liquid tight joint intermediate the stem and the valve A washer 354 is mounted upon the vvalve stem. and .a pin 36 is insertedin ahole drilled transversely of the valve stem t0 prevent downward movementI of the washer on the stem. A spring 37 is held in compres- 60 sion between the washer and the transverseextension of member 30 -to normally hold' the valve stem in a' lowered condition. Thel downward force'of the spring 37 is considerablyA less than that exerted by spring 22' when released. by a fusion of thefusible) element 10, so that the force of the spring 22 upon an actuation thereof will be sufii.

cient to lraise the valve stem against the, tension of the .spring 37 and hold it in such raised position. The lower end 39 of the valve is of conical shape to form al needle` valve of awell known type, and seatsin an opening 38 in a bulkhead '40 aiixed transversely of the tubular chamber 29. A bridged support 41 is provided with a central opening therein of'a size to slidably receive the valve stem, but of smaller diameter than an annular ridge 42, which encircles the valve, to prevent the withdrawal of the needle valve' from theopening in the bridged support. An enlarged opening 43 is drilled in the lower portion of the bulkhead and is threaded to receive the threaded upper end of a Huid regulating member 44. The member 44 is provided with an elongated stern 45 having alflattened lowerehd which permits the member 44 to be readily manipulated manually. The upper end of member 44 is drilled and tapped to receive a small regulating plug 46 threadedly inserted into the hole in the upper end of the'member 44. A hole 47 is drilled inthe small plug to permit the passage of liquid therethrough, and by using plugs with different sizes of apertures the rate of `flow of a liquid therethrough may be regulatedf. A slot 48 cut` sa d,

transversely ofl theksmall plug to permit the manipulation thereof with a screw driver.

A hole 49 is drilled in the sideof the tubular chamber 29 and lis covered by `a. smallcap750 pivotallyr mounted on a' screw 51 threadedly inserted in theside ofthe tubular chamber, and having a sealed condition when the cap 50 is moved to cover the hole 49 inthe wall lof the tube, and an open condition when the member 50 is pivoted about the screw to uncover the hole 49. L A second valve mechanism 52 of similar structure is.-

mounted over a second hole in the tube wall.

A cup 53of a size to telescope freely within the tubular chamber is inserted in 'the lower end thereof and zis rovided with a flanged annular ring .-54 enc1rcling the lower end thereof to receive. a pair of spring l. )uns Y clamps'55 atlixed tothe wall ofthe tubular `chamber by means ofscrews56.

A trigger mechanism 57 is pivotally mounted'upon 'a stud 58 aixed to the platform and is provided with an offset end portion 59 in the 'path of the cup 53 whenthe cup is released, in a manner-to be described later, to drop vertically downward,-and is provided with a hook 60 to engage a circuit closing device D -t o normallyv hold it in an inoperative condition. The circuitl closer is 5125 mounted in a box-like housing 61 of insulative material and comprises a 'rod 62, which may be of bronze,slidably,mounted in an insulai'ive vbu the vhousing 61. A conductiveV bushing 64` Shing 63 affixed in the end of"V i screw 71;

, necdcec tudinally of the platform. A second pir of spring contact members 69 are positioned the `lower i in vertically spaced relation from clips 65 and are mounted upona stop member 70 of conductivematerial held in posi tion in Ythe housing 6l by means of a The lower spring contact members are electrically connected to the upper end of a fuse E, of a well known type,`by means of a conductor 72. rlhe fuseaE is mounted in a well known manner in the box-like housing 3j. The lower end of the fuse E is electri-f cally connected to the lower spring clips 6 in housing 2 by a\conductor 73.A An electrical conductor 74 also connects the support`70 upon which upper contact members are mounted to the upper endof fuse A. Electrical conductors 7 5 and 7 6 are connected into a circuit .with which the device is to be utilized in a well known manner.

The operation of the device is as follows:

A fuse A is inserted in the clips 6 to maintain the tripmechanism B in the inoperative solid line position shown in Figure This permits the spring 37 to force the valve 32 downward toseat the valve in the central opening of the bulkhead 40. A quantity of mercury is then poured into the portion of the tubular chamber above the bulkhead. rlhe circuit closing rod 62 is manually drawn downward and engaged by the hook 60. Cup 53 is held in the solid line position-shown in Figure l by means of the spring clips 55, and a second fuse E is placed in position in the housing 3. The fuse E is held out of the circuit by the gap intermediate the upper spring clips 69 and the end of rod 62.

When the circuit in which fuse A is inserted becomes overloaded to a point which causes a fusion of the fusible element 10, the

, spring 22 raises the plunger 20 and moves the trip mechanism to the dotted line position shown in Figure'l. This raises the valve from its seat in the bulkhead and per- Imits the passage of the mercury contained therein from the upper compartment to the cup 53.- The tension of the spring clips is adjusted to release the'cup whenv a predetermined weight of mercury is Icontained therein. The rate of passage of the mercury` from the upper into the lower compartment may be regulated by the size of the opening in the small plug 46 inserted in the top of member 44. When a predetermined weight lwith the timing of mercury is contained in the cup, the force Vof gravity thereon overcomes the sustaining power of the spring clips 55 and the cup drops, thereby moving the release lever 57 about its pivot and causing kthe hook 60 to release the circuit closing plunger 62. rlhe circuit closing plunger is thrown upward by the force of the coil spring 66 and engages upper spring contacts 69 to close the circuit and thereby place 'the fuse lE in the circuit.

lf desired, a second fuse similar to fuse A may `be used instead of an ordinary fuse E illustrated, and a second timing mechanism similar to that illustrated and described may be used in connection with such fuse to cut in a third fuse, not shown7 in the same manner as fuse E described and illustrated, is cut in. The number of fuses to be used is entirely optional with the user.

While a. timing mechanism suchas that desciibedand illustrated isV suitable for the purpose specified, it is not desired to limit the construction to such a timing mechanism but to include any timing mechanism of a well known type in the combination.

What l claim is:

l. A device of the character described, comprising a fusible element,V` trip means having a set condition and an operated con-:1, dition, resilient means operatively connected to the fusible element and tothe trip means to cause an actuation of the trip means upon a breaking of the fusible element, a timing mechanism operatively connected to the trip means switch means operatively associated element to be operated by the timing element, a predetermined interval after the actuation thereof, and a second fusible element to be normally electrically disconnected from the first fusible element and to be electrically connected in parf allel therewith upon an* actuation of the switch means.

2. A device of the character described, comprising a housing, a fusible element removably mounted therein, a movable member connected to the fusible element, resilient means held in'compression by the movable member when lconnected to the fusible element, timing mechanism operatively associated with the movable member to have a normal condition and a released condition,

and mechanically actuated circuit-closing -ineans operatively associated with the timloo f mally retain the cup in a raisedecondition ltrigger means by the'cup,

. fusible element to be connected-by the circuit and-to release the cup for downward movement when a predetermined weight of liquidJ is contained in said cup, trigger means. lmounted in the path )of the cup when released fcrrdownward movement to be actulated by a downward movement of said cup;

wcircuit .closing means normally held in an open condition'by said trigger means to be released thereby upon an actuation of said and a secondary -closer in-parallelism with the first fusible element upon an actuation of the circuit closing means. ,l

4. A device of the character described, comprising a fusible element, movable means e having a normal condition land an actuated :trigger means havingb condition, to be heldin a normal `condition by the fusible element, timing means operatively associated with themovable element, a set condition and a released condition to e released by said timing mechanism a predetermined time after theactuation ofthe timing mechanism, circuit closing.' means operatively associated with the trigger means to be normally held 'of said circuit closing means,

in an open condition thereby, resilient means to move the circuit closing means to a closed condition upon the release by said trriggerA and a second- `upon the ary fusible element normally velectrically disconnected from the first fusible element to be connected in parallel with the first fusible element upon the actuation 'of the` circuit closing means. L y y 5. Ai, device of the character described,- comprising a fusible element, a normally unoperated timing mechanism operatively as-y sociated with the fusible 'element to be operated upon the fusingv of said fusible element, av movable portion of said' timing mechanism being actuated upon the completion'of a'l predetermined time interval, mechanically actuated circuit closing means having a releasing .element therein operatively associatedwth the timing mechanism to normally hold said'xcircuit closing means in an open condition and to be actuated by the movable portion VTof the timing mechanism upon an actuation thereof torelease 'i said circuit closing means for closing v,6. A device of the character described, eompnsing a fusible element, trip means associated therewith to be held in a normal timing means mounted condition thereby,

to be operated by adjacent said trip means a release of said trip means, tion of said timing means being actuated completion of a predetermined time mechanically actuated circuit closinterval,

`associated with said meing means, means chaneally actuated circuit closing means to urge said circuit closing means to a closed condition, and trigger means normally holding said circuit closing means in an open conditionv and of the movable portion of said timing mechanism to releaselsaid circuit closing means for closing. l

-In testimony whereof I affix my signature.

PAUL o. MCKENDRICK,

a movable porbeing moved by anY actuation 

